Multilayer print film having incorporated coloring material



1960 s. s. FIERKE ET AL 2,947,628

MULTILAYER PRINT FILM HAVING INCORPORATED COLORING MATERIAL.

Filed Oct. 12, 1956 GREEN SENSITIVE SILVERHALIDE MAGENTA OPTICALSENSITIZING DYE ABSORBED ON INTERNAL LATENT IMAGE SILVER HAL/DE--'\-RED-SEN$/T/VE SILVER HAL/0E- CYAN OPTICAL sENsITIzINs DYE ABSORBEDON INTERNAL LATENT IMAGE EMULSION BLUE SENSITIVE SILVER HAL/DE-$EN$ITIVE SILVER HAL/DE LOIDAL SILVER FILTER LAYER GREEN -$EN$ITIVESILVER HAL/DE .Ffi 2 FILTER LAYER CONTAIN/N6 cmN OP77CAL SENSITIZ/NG DYEAs- SORBED 0N INTERNAL LATENT IMAGE SILVER HAL/DE RE D SENSITIVE SILVERHAL IDE Sclleuring J1 Fierke HomerWJCre ssman IN V EN T 0R5 .ITTTORNEY &AGENT United States P t n MULTILAYER PRINT FILM HAVING INCOR- PORATEDCOLORING MATERIAL Scheuring S. Fierke and Homer W. J. Cressman,Rochester, N.Y., assignors to Eastman Kodak Company, Rochester, N.Y., acorporation of New Jersey Filed Oct. 12, 1956, Ser. No. 615,546

7 Claims or. 96-74 This invention relates to photography andparticularly to a multi-layer photographic film having a light filteringmaterial incorporated therein.

In the usual sensitivity arrangement of three-layer photographic film,the red-sensitive emulsion layer is coated adjacent the support and thisis followed in order by the green-sensitive emulsion layer and theblue-sensitive emulsion layer. It is customary to form a cyan dye imagein the red-sensitive layer, a magenta dye image in the green-sensitivelayer and a yellow dye image in the blue-sensitive layer. It is alsowell known that a difierent sensitivity arrangement may be used in whicheither the red sensitive layer or the green sensitive layer is coatedoutermost for the purpose of improving definition. It is well known thatthe definition of the resulting color picture is determined to a largeextent by the cyan and magenta dye image and that the overall definitioncan be improved by arranging the three emulsion layers so that the layercontaining the cyan or magenta dye image is outermost and the layercontaining the yellow dye image is adjacent the support or farthest fromthe eX- posing light. This arrangement is described, for example, inBaker US. Patent 1,867,301 and Tarbin U.S. Patent 1,871,479.

When this inverted sensitivity order is used, it is frequently necessaryto employ a blue-sensitive emulsion layer, that is, the layer adjacentthe support, having a higher blue light speed than would be required ifthe blue-sensitive layer were outermost. Whether for'this or otherreasons, it has been found that the blue-sensitive emulsion layer tendsto scatter any red or green light reaching it after passing through theupper layers and reflect part of it back to the upper layers, andthereby to reduce the overall definition of the resulting picture. Thislight scattering in the bottom layer of the film is a serious defect infilms using this sensitivity arrangement. It is therefore an object ofthe present invention to provide a novel means for preventinglight-scattering in multilayer films, either of light passing to loweremulsion layers, or of light reflected from lower to upper emulsionlayers. A further object is to retain theadvantages of coating thegreen-sensitive or red-sensitive layer outermost in a multi-layer filmand at the same time to reduce or overcome the disadvantage of lightscatter caused by the blue-sensitive emulsion, layer. A further objectis to provide a novel multi-layer photographic film.

These objects are accomplished by including in one of the layers such asone or more of the emulsion layers or an organic colloid interlayer, aninternal latent image silver halide emulsion to which is adsorbed anon-image forming coloring material such as one or more opticalsensitizing dyes for silver halide absorbing up to 100% of the light towhich any emulsion layer above the colored layer is sensitive andsubstantially no light to which an emulsion layer below the coloredlayer is sensitive, and when present in an emulsion layer, the coloringmaterial absorbing up to 75% of the light to which that emulsion ice 'silver halide developing agents to form dyes and generally thecolor-forming compound in each emulsion is selected to form dye imagesof color complementary to the sensitivity of the emulsion layer.

The function of the internal latent image emulsion component of thered-sensitive or green-sensitive emulsion-layers or the interlayer is toprevent the wandering of the dyes from grain to grain in the emulsionlayer or from emulsion to emulsion. Since the internal latent imageemulsions are not developable in the surface developers used indeveloping the color filmsdescribed,'they do not interfere with theformation of the colored images in the emulsion layers but since theinternal latent image emulsions are readily removable from the films inthe processing solutions such as the fixing bath, the coloring materialis removed from the emulsion layers together with the internal latentimage emulsion during the proc-- essing steps.

One advantage of the use of the internal latent image emulsions to whichthe red-absorbing or green-absorbing dyes are adsorbed, resides in thefact that since nonwandering narrow-band absorbing dyes are .used, theover-all speed of the emulsions is higher by as much as, 0.6 to 0.8 logE than when wider band absorbing and more diifusiblecoloring materialsare used for coloring the emulsion layers.

The accompanying drawing shows in cross-sectional view, twomodifications of our invention wherein Fig. 1 shows the support 10,suchas a cellulose ester film, base, having thereon a blue-sensitiveemulsion layer] 11, a red-sensitive emulsion layer 12 containing acyanor red-absorbing dye adsorbed onto internal latent image emulsionand a green-sensitive emulsion layer 13 containing a magenta orgreen-absorbing dye adsorbed onto an internal latent image emulsion,Fig. 2 shows the suppor t lfl having sensitive emulsion layers 14,15 and11 sensitive respectively to red, green and blue light, a colloidalsilver filter layer 16, and a layer 17 containing magenta opticalsensitizing dye adsorbed on, internallatent image silver halide. t

Thefilm used according to. the preferred embodiment of our inventionconsists of. a suitable support such as cellulose ester, synthetic resinor paper having on one side thereof, suitable subbing layers andablue-sensitive silver halide emulsion layer coated thereon. This isfollowed by green-sensitive and red-sensitive silver halide emulsion.layers either of which maybe outermost, although we prefer to coat thegreen-sensitive emulsion layer last or outermost. Since thegreen-sensitive and red-sensitive silver halide emulsions are sensitiveto blue or violet light in addition to the regions to which they areoptically sensitized, it is necessary to prevent the action of'blue orviolet light on these layers. This may be accomplished either by usingas the bottom layer a blue-sensitive emulsion which has much higher bluespeed than the green sensitive and red-sensitive emulsions and exposingthe entire film through a yellowfilter which absorbs all blue light towhich the upper layers are sensitive but not all blue light to which thebottom layeris sensitive orby, using in the upper layers emulsionsconsisting principala Patented -Aug. 2,- 196i) ly of silver chloridewhich has very little sensitivity in the visible blue light region. Theemulsion layers contain couplers incorporated as described in Jelley andVittum U.S. Patent 2,322,027.

According to the preferred embodiment of our invention, theblue-sensitive layer is a silver bromide or silver chlorobromideemulsion sensitive to visible blue light and containing a couplercapable of forming a yellow dye image. The red-sensitive andgreen-sensitive emulsions are silver chloride or silver chlorobromideemulsions relatively insensitive to visible blue light and containing,respectively, couplers capable of producing cyan and magenta dye images.

The optical sensitizing dyes for silver halide which are adsorbed ontothe internal latent image emulsions have narrow-band absorptionsprimarily in the green or red spectral regions and are strongly adsorbedto the internal latent image emulsion. For example, readily solublecyanine dyes containing fi-naphthothiazole, S-phenylbenzotriazole,S-chlorobenzotriazole, and -phenylbenzoxazole nuclei are suitable aswell as hemi-cyanines, hemioxanols and merocyanines, in particular thepartially solubilized merocyanines, examples of which appearhereinafter.

The internal latent image silver halide emulsions to which the coloringmaterials are adsorbed are well known in the art. The internal latentimage emulsions are emulsions which form latent images mostly inside thesilver halide grains. An internal latent image emulsion, as described onpages 296 and 297 of Mees The Theory of the Photographic Process, 1942,is especially useful in our invention. Most of the internal latent imageemulsions are silver bromo-iodide emulsions of high iodide content,preferably containing at least l0%- 20% 0f iodide. Burtons emulsion isan emulsion of this type, having a silver iodide content ofapproximately 40% of the content of silver halide. It is not absolutelyessential, however, for the emulsion to contain silver iodide.

Burtons emulsion described in Wall, Photographic Emulsions, 1929, pages52 and 53, is prepared as follows:

B is heated to 70 C., and A, cold, added to B with constant shaking,digested for 20 minutes at 50 C., and

allowed to cool slowly. C is added after being allowed to swell for 20minutes in water, drained and melted. The emulsion is then set andWashed.

An internal latent image emulsion made as described in the Davey andKnott US. Patent 2,592,250 is particularly useful in our invention. Thisemulsion is prepared by first forming in the absence of ammonia and inone or more stages silver salt grains consisting at least partly of asilver salt which is more soluble in water than silver bromide,subsequently converting the grains to silver bromide or silverbromoiodide and if the silver iodide content of the emulsion is lessthan 6% calculated on the total silver halide, treating such grains withan iodide compound to bring the silver iodide up to at least 6%,ripening preferably in the absence of ammonia and then either washingout some of the soluble salts or washing out the whole of the solublesalts, fol lowed by the additionof soluble salts such as solublechloride or bromide. An example of an emulsion made in this way is asfollows:

Solution No. 1:

Inert gelatin 20 grams KCl 20 grams} at 40 C. Water 560 cc. Solution No.2:

KCl 100 grams a Water 520 cc. i at 45 Solution No. 3: V

AgNO 195 grams Water 520 cc. i at 45 Solution No. 4:

KBr 160 grams KI 40 grams} at 45 C. Water 500 cc.

Run solutions Nos. 2 and 3 simultaneously into solution No. 1 in avessel, taking seconds to do this. Then ripen for 1 minute at 45 C. Nextadd solution No. 4, then ripen for 20 minutes at 45 C. Next add 235grams of inert gelatin (dry). Then ripen at 45 C. for 15 minutes duringwhich time the gelatin dissolves. Set and shred the emulsion and thenwash until free from all soluble bromide and then add about 150 cc. of10% solution of KCl (by weight), and then add water to make 3 /2 liters.The tanning developing agents such as described hereinafter may then beadded to the melted emulsion.

An internal latent image type of silver halide emulsion may be definedas one which, when a test portion is exposed to a light intensity scalefor a fixed time between and 1 second, and developed for 4 minutes at 20C. in the ordinary, surface developer (Example I), exhibits a maximumdensity not greater than /3 the maximum density obtained when the sameemulsion is equally exposed and developed for 3 minutes at 20 C. in aninternal type developer (Example II). Preferably the maximum densityobtained with the surface developer is not greater than the maximumdensity obtained when the same emulsion is developed in the internaltype developer. Stated conversely, an internal latent image emulsion,when developed in an internal type developer (Example II) exhibits amaximum density at least 5, and preferably at least 10, times themaximum density obtained when the same emulsion is exposed in the sameway and developed in a surface developer (Example I).

An ordinary, surface-type developer, that is, one which develops animage only on the surface of the grains of an internal latent imageemulsion, is the following:

Example I Grams p-Hydroxyphenylglycine v 10 Sodium carbonate (crystals)100 Water to 1 liter. 7 Development time, 4 min. at 20 C.

An internal type developer, that is, one which develops an image insidethe grains of an internal latent image emulsion, is the following:

Water to 1 liter. Development time, 3 min. at 20 C. Y

- 1 "m. ll"...

5, Our invention will now be illustrated by the following examples:Example 1.--Red-sensitive emulsion containing red absorber adsorbed tointernal latent image emulsion To a mixture, preheated to 40 C., of616.0 g. of an internal latent image emulsion prepared by the method ofDavey and .Knott above, containing per mole of silver 41.0 g. of a cyandispersion comprising 3.6 g. ofl-hydroxy-2-[-(2,4-diamylphenoxy)-n-butyl] naphthamide, 0.45 g. of2-hexadecyl-S-methylhydroquinone, 8.1 g. of di-n-butyl phthalate, 24.6g. of a 10% deashed gelatin solution, and 3.05 ml. of a 5% Alkanol Bsurfactant solution 214 g. of a red-sensitized chlorobromide emulsion(80 1 percent silver chloride, 20 percent silver bromide) containing 239grams of gelatin per mole of silver halide in a total weight of 4280grams per mole .00895 g. of benzothiazole methiodide in 5.3 ml. of water0.141 g. of mucochloric acid in 5.2 ml. of water 15 ml. of 7 /2% saponinsolution Water to a total weight of 525 g.

This red-sensitive emulsion containing a cyan-forming coupler can becast on a film support provided with a blue-sensitive yellow-formingcoupler-containing emulsion layer at a rate of about 17.7 grams persquare foot. Over the red-sensitive emulsion layer is coated agreensensitive emulsion layer containing a magenta-forrning coupler anda green light absorbing dye as provided in the following examples. Theelement can then be exposed in the conventional manner, for example, toa suitable multilayer color negative and dye images developed therein bymeans of color development. Following removal of the silver images andresidual silver halide in the film by bleaching and fixing operations,it is found upon examination of the dye images that the redabsorbing dyeadsorbed to the internal latent image emulsion component of thered-sensitive emulsion layer has been removed in the processingsolutions along with the internal latent image emulsion, and the dyeimages possessed a high degree of sharpness. The mentioned speedadvantages wereobtained in this case sincethe thiacarbocyanine dye wasstrongly adsorbed to the internal. latent image emulsion and the dye hada narrow absorption band with a peakabsorption at 680 millimierons.

Example 2.Red-sensitive emulsion containing red absorber adsorbed tointernal latent image emulsion An internal latent image emulsion 193.0g. prepared by the method of Davey and Knott above, containing per moleof silver halide 139.0 g. of gelatin in a total weight of 1930.0 g. wastreated with 30 mg. ofanhydro-3,3-dip-carboxyethyl-5,5'-dichloro-9-ethylthiacarbocyaninehydroxide in 3.0 ml. of a 1% triethylamine solution diluted toa totalvolume of 30 ml. with methanol. The weight of the sensitized. emulsionwas 220.0 g. r

The final emulsion was then made by mixing the following components: r

88g; of the above internal latent image emulsion containing thethiacarbocyanine red absorber 32.8 g; of the cyan dispersion of Example1 55.5 g. of a 10% deashed gelatin solution 171.0 g. of thered-sensitive chlorobromide emulsion used in' Example 1.

.0071 g. of benzotriazole methiodide in 4.2 ml. of water .0925 g. ofmucochloric acid in 3.4 ml. of water 10 ml. of 7 /z% saponin solutionWater to total weight of 344.0 g.

This emulsion can be coated at 14.4 g. per square foot and used asdescribed in Example 1 as the red-sensitive emulsion over ablue-sensitive emulsion. When the thiacarbacyanine dye is used asdescribed as a red absorber, spectrophotometric curves showed anarrow-band absorption with a peak at 642 millimicrons.

Example 3.Red-sensit'ive emulsion containing red absorber absorbed tointernal latent image emulsion The procedure of Example 2 was repeatedexcept using as a red absorber in the internallatent image emulsion thedye 3,3-diethyl-5,5-9-triphenylthiacarbocyanine-ptoluene sulfonate. Whenthe emulsion was employed in a color film as described in Example 1,sharp images were obtained due to the sharp absorption band of the dyehaving a peak at- 626 millimierons.

Example 4.-Green-sensitive emulsion containing green absorber adsorbedto internal latent'image emulsion The internal latent image emulsion(308.0 g.) described under Example 1 was treated in an analogous mannerwith 20 mg. of 3,3'-9-triethyl-5,5'-diphenyloxacarbocyanine iodidedissolved in 0.4 ml. of pyridine and 25.0 ml. of acetone. The weight ofthe sensitized emulsion was 315.0 g.

The final emulsion was prepared by mixing the followmg: l

95 g. of the above internal latent image emulsion containing theoxacarbocyanine green absorber 39.5 g. of a magenta dispersioncontaining 2.7 g. 'of 1- (2,4,6-trichlorophenyl) -3 3-2(2,4'-di-tertamyl phenoxyacetamido)-benzamido] -5-pyrazolone, 0.63 g. of

2,5-dioctylhydroquinone, 6.65 ml. of 'tri-o-cresyl phosphate, 23.8 g. ofa 10% deashed gelatin solution, and 1.97 ml. of a 5% Alkanol B solution134.0 g. of a green-sensitized chlorobromide emulsion percent silverchloride, 20 percent silver bromide) containing 239 grams of gelatin permole of silver halide in a total weight of 4,430 g.

0.0054 g. of benzotriazole methiodide in 3.2 ml. of water 0.0896 g. ofmucochloric acid in 3.3 ml. of water 10.0 ml. of a 7 /z% saponinsolution Water to a total weight of 330.0 g.

When the emulsion was used as described in Example 1 as thegreen-sensitive emulsion in conjunction with'the red-sensitive emulsionof Example 1, a high degree of sharpness was obtained in the dye imagesand the green and red absorbers were readily removed with the internal.latent image emulsions in the fixing bath employed after colordevelopment.

Example 5.-Green-sensitive emulsion containing green absorber adsorbedto internal latent image emulsion The green absorber3,3'-diethyl-4,5;4,5-dibenzothiacyanine iodide was incorporated into aninternal latent image emulsion just as described in Example 2.

The final emulsion was made by mixing the following:

This emulsion Was employed as a green sensitive emul sion in the mannerdescribed in Example 1. The image sharpness benefits were derived inpart from the narrow absorption at 494 millimicrons.

It will be apparent that 'the above representative marrow-band red orgreen absorbers can be incorporated separately or in admixture in thered or green-sensitive emulsions of the color films described. However,as indicated above, it is preferred to incorporate a red absorber in thered-sensitive cyan-forming, coupler-containing emulsion layer overlyingthe blue-sensitive emulsion layer and thereover a green absorber in agreen-sensitive emulsion layer containing magenta-forming coupler.

The multilayer material in which our internal image emulsions havingadsorbed optical sensitizing dyes are incorporated may have thesensitive emulsions arranged in any order, that is, with theblue-sensitive emulsion nearest the support or with the green-sensitiveor red-sensitive emulsion nearest the support. The internal imageemulsion having adsorbed optical sensitizing dye may be in any of theseemulsion layers or in an interlayer between emulsion layers, or in anunder layer between the support and the emulsion layers, or in a backinglayer or overcoating layer. Black and white single-emulsion-l ayer filmsmay also have the internal image absorbing layer as an overcoat,undercoat or backing layer.

What we claim is:

l. A multilayer photographic element comprising 7 a support having onone side thereof three silver halide emulsion layers separatelysensitive to the blue, green and red spectral regions, and eachcontaining non-diffusing color-forming compounds capable of couplingwith the oxidation product of a primary aromatic amino silver halidedeveloping agent to form dyes, and in at least one layer on said side ofthe support an internal latent image silver halide emulsion, the silverhalide grains of which are such as to cause a test portion of saidlatter emulsion upon exposure to a light intensity scale for a fixedtime between 1 and 1 second and development for} minutes at 20 C. in thefollowing internal type developer:

Water to =1 liter to give a maximum density at least 5 times the maximumdensity obtained when the equally exposed silver halide emulsion isdeveloped for 4 minutes at 20 C. in the following surface developer:

Grams p-Hy droxyphenylglycine Sodium carbonate 100 Water to 1 liter. 1

to which emulsion layer is adsorbed a dye absorbing a major amount up to100% of the light to which any emulsion above the colored layer issensitive and substantially no light to which an emulsion layer belowthe dyed emulsion layer is sensitive, and when present in an em-ulsionlayer, the dye adsorbing a major amount up to 75% of the light to whichsaid last-mentioned emulsion layer is sensitive, said blue, green andred-sensitive emulsions being of theordinary type developable in asurface developer and incapable of development to said densitydifference under said' test conditions.

2. A multilayer photographic element comprising a support having on oneside thereof three silver halide emulsion layers separately sensitive tothe blue, green and red spectral regions and each containingnon-diffusing color forming compounds capable of coupling with theoxidation 'product'of a primary aromatic amino silver halide developingagent to form dyes, said blue-sensitive emulsion layer beingadjacentsaid support and having an appreciably higher blue speed thansaid green-sensitive and red-sensitive emulsions, and in at least onelayeron said side of the support an internal latent image silver halideemulsion'th'e silver halide grains of which are such as to cause a testportion of said latter emulsion upon exposure to a light intensity scalefor a fixed time between and 1 second and development for 3 minutes at20 C. in the following internal type developer: 7

Grams Hydroquinone 15 Monomethyl-p-aminophenol sulfate '15 Anhydroussodium sulfite Q. 50 Potassium bromide 10 Sodium hydroxide 25 Sodiumthiosulfate 20 Water to 1 liter I to give a maximum density at least 5times the density obtained when the equally exposed silver halide,emulsion is developed for 4 minutes at 20 C. in the following surfacedeveloper:

Grams p-Hydroxyphenylglycine 10 Sodium carbonate 100 Water to 1 liter towhich is adsorbed a dye absorbing a major amount of visible light towhich one of said green-sensitive and red-sensitive emulsion layers issensitive and a minor amount of blue light. V v

3. A multilayer photographic element comprising a support having on oneside thereof three integrally united silver halide emulsion layersseparately sensitive to the blue, green and red spectral regions andeach containing non-difiu'sing' color-forming compounds capableofcourpling with the oxidation product of a primary aromatic aminosilver halide developing agent to form dyes, said' blue-sensitiveemulsion layer being adjacentsaid support and having an appreciablyhigher blue speed than said green-sensitive and red-sensitive emulsions,and in at least one of said emulsionlayers other than the blue-sensitiveemulsion layer an internal latent image silver halide em'ule sion thesilver halide grains of which are such as to cause a test portion ofsaid latter emulsion upon exposure to.

a light intensity scale for a fixed time between A0 and 1 second anddevelopment for 3 minutes at 20 C in the following internal typedeveloper:

Water to 1 liter V to give a maximum density at least 5 times themaximum density obtained when the equally exposed silver'halide emulsionis developed for 4 minutes at 20 C. in the following surface developer:

p-Hydroxyphenylglycine l0 Sodium carbonate 100 Water to 1 liter to whichis adsorbed a dye absorbing a major amount of visible light to which oneof said een-sensitive and red-' sensitive emulsion layers is sensitiveand a minor amount of blue light.

4. The photographic element of claim 3 wherein the three emulsion layerson the support are sensitized; in order to the blue, red and greenspectral regions.

5. A multilayer photographic element comprising a;

support having on one side thereof three integrally united silver halideemulsion layers separately sensitive to the' blue, green and redspectral regions and each containing Grams non-difiusing color-formingcompounds capable of coupling with the oxidation product of a primaryaromatic amino silver halide developing agent to form dyes, saidblue-sensitive emulsion layer being adjacent said support and having anappreciably higher blue speed than said green-sensitive andred-sensitive emulsions, and in said red-sensitive emulsion layer aninternal latent image silver halide emulsion the silver halide grains ofwhich are such as to cause a test portion of said latter emulsion uponexposure to a light intensity scale for a fixed time between and 1second and development for 3 minutes at 20 C. in the following internaltype developer:

Grams Hydroquinone l Monomethyl-p-aminophenol sulfate 15 Anhydroussodium sulfite 50 Potassium bromide Sodium hydroxide 25 Sodiumthiosulfate 20 Water to 1 liter to give a maximum density at least 5times the maximum density obtained when the equally exposed silverhalide emulsion is developed for 4 minutes at 20 C. in the followingsurface developer:

I I Grams p-Hydroxyphenylglycine 10 Sodium carbonate 100 Water to 1liter to which is adsorbed a dye absorbing a major amount of red light,and in said green-sensitive emulsion layer said internal latent imagesilver halide emulsion to which is adsorbed a dye absorbing a majoramount of green light.

6. The photographic element of claim 5 wherein the red-sensitive layeris superposed over the blue-sensitive emulsion layer and thegreen-sensitive emulsion layer is outermost.

7. A multilayer photographic element comprising a support having on oneside thereof three integrally united silver halide emulsion layersseparately sensitive to the blue, green and red spectral regions andeach containing nondifiusing color-forming compounds capable of conplingwith the oxidation product of a primary aromatic amino silver halidedeveloping agent to form dyes, said blue-sensitive emulsion layer beingadjacent said support and having an appreciably higher blue speed thansaid green-sensitive and red-sensitive emulsions, and in an interlayerbetween said blue sensitive emulsion layer and the outermost emulsionlayer an internal latent image silver halide emulsion the silver halidegrains of which are such as to cause a test portion of said latteremulsion upon exposure to a light intensity scale for a fixed timebetween i and 1 second and development for 3 minutes at 20 C. in thefollowing internal type developer:

Water to 1 liter to give a maximum density at least 5 times the maximumdensity obtained when the equally exposed silver halide emulsion isdeveloped for 4 minutes at 20 C. in the following surface developer:

Grams p-Hydroxyphenylglycine 10 Sodium carbonate Water to 1 liter towhich is absorbed a dye absorbing a major amount of visible light towhich one of said green and red-sensitive emulsion layers is sensitiveand a minor amount of blue light.

References Cited in the file of this patent UNITED STATES PATENTS1,879,806 Kelley Sept. 27, 1932 2,456,954 Knott et 'al Dec. 21, 19482,456,956 Knott et al Dec. 21, 1948

1. A MULTILAYER PHOTOGRAPHIC ELEMENT COMPRISING A SUPPORT HAVING ON ONESIDE THEREOF THREE SILVER HALIDE EMULSION LAYERS SEPARATELY SENSITIVE TOTHE BLUE, GREEN AND RED SEPECTRAL REGIONS, AND EACH CONTAININGNON-DIFFUSING COLOR-FORMING COMPOUNDS CAPABLE OF COUPLING WITH THEOXIDATION PRODUCT OF A PRIMARY AROMATIC AMINO SILVER HALIDE DEVELOPINGAGENT TO FORM DYES, AND IN AT LEAST ONE LAYER ON SAID SIDE OF THESUPPORT AN INTERNAL LATENT IMAGE SILVER HALIDE EMULSION, THE SILVERHALIDE GRAINS OF WHICH ARE SUCH AS TO CAUSE A TEST PORTION OF SAIDLATTER EMULSION UPON EXPOSURE TO A LIGHT INTENSITY SCALE FOR A FIXEDTIME BETWEEN 1/100 AND 1 SECOND AND DEVELOPMENT FOR 3 MINUTES AT 20*C.IN THE FOLLOWING INTERNAL TYPE DEVELOPER: